Different types of link rods for suspending a spring-supported wheel in a vehicle are known. It is their function to guide the wheel in its motion relative to the vehicle while driving. Therefore it is important for such link rods to have a high rigidity at low weight. Moreover, due to limited space they should have a slim build. These prerequisites are met in comparison to solid link rods mainly by link rods made of sheet metal shells.
A link rod of the above-mentioned type known from a patent document (DE 103 34 192 A1) can be formed comparatively simple by a drawing and subsequent bending process. Thus a more complex manufacturing step of welding can be omitted. However, in this link rod only plain holes are provided for bearing eyes. This means that additional means for receiving bearing bushings must be provided either in the holes or at the bushings proper. Also, its rigidity is far from optimum due to the simple apertures for the bearing eyes. It is not known if such a link rod has been used in practice.
In a known method for manufacturing a link rod of the above-mentioned type (WO 02/074562 A2) holes having inner bearing support surfaces are formed in a flat sheet metal blank. Then, in two sequential process steps, the first limb of the U-shaped profile to be produced and then the second limb of the U-shaped profile to be produced are each bent by 90° so that the back connecting both limbs is formed and both limbs are in parallel to each other. This way of manufacturing makes it difficult to exactly align the holes providing the common bearing surfaces with each other.